DESCRIPTION (Applicant's Abstract): Between 1978 and 1981, the NIMH Collaborative Depression Study conducted thorough baseline evaluations of 955 probands with major affective disorder. Probands were followed at semiannual and annual intervals to 10 years with a retention rate of 70.1% of those still living. A further extension of this follow-up is currently underway and a full 16-year follow-up will be available by the end of 1996. The U01 grant for the extended follow-up, however, did not include support for data analysis. Investigators at the Iowa Center obtained this through the R01 mechanism and used the three years of support to produce 18 refereed journal articles describing the course of affective illness over a 10-year period. We now seek a competitive renewal to analyze data from the full 18 years. Earlier CDS analyses have emphasized the course of index episodes, the time to subsequent clinical events, and the long-range prognostic qualities of baseline measures. We have since shifted emphasis to the timing and phenomenology of prospectively observed episodes and to overall trends apparent across repeated observations. The prospective nature of the available assessments provides unprecedented opportunities to describe the long-term course of the major affective disorders without the biases attending attempts to recall remote events. Moreover, newly available statistical methods will allow the assessment of treatment effects on morbidity and risk for suicide.